Conflicting Role of Water in the Activation of H2O2 and the Formation and Reactivity of Non-Heme Fe(III)-OOH and Fe(III)-O-Fe(III) Complexes at Room Temperature

Inorg Chem. 2016 May 2;55(9):4211-22. doi: 10.1021/acs.inorgchem.5b02976. Epub 2016 Apr 13.

Abstract

The formation of an Fe(III)-OOH species by reaction of complex 1 ([(MeN3Py)Fe(II)(CH3CN)2](2+)) with H2O2 at room temperature is reported and is studied by a combination of UV/vis absorption, EPR, and resonance Raman spectroscopies. The formation of the Fe(III)-OOH species, and its subsequent conversion to relatively inert Fe(III)-O-Fe(III) species, is shown to be highly dependent on the concentration of water, with excess water favoring the formation of the latter species, which is studied by UV/vis absorption spectroelectrochemistry also. The presence of acetic acid increases the rate and extent of oxidation of 1 to its iron(III) state and inhibits the wasteful decomposition of H2O2 but does not affect significantly the spectroscopic properties of the Fe(III)-OOH species formed.

MeSH terms

  • Acetic Acid / chemistry
  • Acetonitriles / chemistry
  • Alkenes / chemistry
  • Coordination Complexes / chemistry*
  • Electrochemical Techniques
  • Hydrogen Peroxide / chemistry*
  • Iron Compounds / chemistry*
  • Kinetics
  • Ligands
  • Oxidation-Reduction
  • Temperature
  • Water / chemistry*

Substances

  • Acetonitriles
  • Alkenes
  • Coordination Complexes
  • Iron Compounds
  • Ligands
  • Water
  • Hydrogen Peroxide
  • Acetic Acid
  • acetonitrile